Floor grinding apparatus

ABSTRACT

A grinding apparatus for grinding a surface includes a plurality of satellites, a carrier for supporting the plurality of satellites, a plurality of primary gears rotatably mounted within the carrier and disposed about a motor output, a static gear which is fixed with respect to the motor and co-axial with the motor output, and a plurality of secondary gears which each rotate with one of the primary gears. The primary gears rotate the satellites with respect to the carrier and the secondary gears rotate the carrier around the static gear.

FIELD OF THE INVENTION

The present invention relates to an apparatus for processing a surface.More particularly, in its preferred intended use, the present inventionrelates to a grinding apparatus.

BACKGROUND OF THE INVENTION

Floor grinding apparatuses and the like are very well known in the art.

Conventional floor grinding apparatuses are usually provided, alone orin combination with other similar apparatuses, as part of larger floorgrinders, mounted on movable chassis that can travel along a givensurface. The chassis of the apparatus can be provided with wheels and ahandle so as to be movable by an operator around a work area, or can bemounted onto a motorized chassis, such as a cart, and driven. Thegrinding apparatus typically comprises a motor which drives one or moregrinding disks. Each grinding disk comprises a grinding surface on abottom side and rotates about its axis, thereby grinding the floor whenin contact therewith.

U.S. Pat. No. 3,128,581 to Tesetti discloses a prior art grindingapparatus including a set of three grinding stones which are eachoperable to rotate about a respective axis. U.S. Pat. No. 4,319,434 toBrejcha discloses a prior art surface processing machine including a setof six processing tools fixed in a spaced apart relationship andoperable to rotate about a common central axis.

A major drawback associated with conventional types of grindingapparatus is that they are likely to produce an unequal, wavy surfacedue to the uneven weight and grinding distribution. Specifically, it isknown that the weight on the grinding discs is higher in the centerwhere the motor is typically placed and that the pressure on the discstherefore diminishes outside that area. Furthermore, it is known thatthe grinding disks of such apparatuses are often arranged to partiallyoverlap in order to ensure that no area beneath the apparatus is missed.The combination of these two factors results in that, as the apparatustravels over a work surface, more material may be removed along thecentre of the apparatus than along its the lateral sides. This effect isespecially pronounced on soft or medium-hard surfaces. Because the endresult is irregular, these conventional apparatuses are only suitablefor surface preparation and coating overlay removal, rather than surfacefinishing which typically requires a uniform finish.

It is also known to provide a combination of the two patents mentionedherein above wherein a plurality of grinding disks, called “satellites”,are operable to rotate not only about their own axis, but also an axiscentral to the grinding apparatus. Such a motion, that is the individualrotation of the satellite grinding disks and the rotation of these disksabout a central axis, is called a “planetary” motion.

U.S. Pat. No. 383,147 to Burgess discloses a floor cleaning machineincluding a planetary gear system wherein a pair of satellites which areattached to respective gears mounted between a driven spur gear and anouter crown gear. Similarly, U.S. Pat. No. 2,171,060 to De Spirtdiscloses a floor surfacing machine wherein a set of satellites aremounted to a casing which is fixed to a motor drive shaft. The rotationof the casing pushes satellites around a main gear, causing them torotate with respect to the casing as well.

U.S. Pat. No. 7,140,957 to Thysell et al. discloses a belt drivenplanetary grinding apparatus. A belt rotates a set of four satelliteswith respect to a planet wheel, as well as rotating the planet wheelwith respect to the apparatus.

While a planetary grinding apparatus is generally preferable to anon-planetary one, a major drawback associated with this conventionaltype of belt driven grinding apparatus, also called a passive planetaryapparatus, is that such friction-driven power transmission is prone toslippage, which creates an uneven and non-uniform grinding effect.Moreover, this limits the torque applied to, and by, the device andbecause of this conventional grinding apparatuses such as this arelimited in their speed of operation. It is also known that duringextended operation such belt-driven grinders are subject to beltfailure, which is time consuming and costly to repair.

Also known to the Applicant are the following US patents andinternational patent laid-open application which describe other grindingapparatuses and the like: U.S. Pat. No. 593,220, U.S. Pat. No.1,984,205, U.S. Pat. No. 2,316,886, U.S. Pat. No. 4,342,485, U.S. Pat.No. 5,643,047, and WO 2005/077599.

In all cases, there is a need for an improved grinding apparatus whichis active planetary and can operate at higher torque and/or higher speedthan conventional apparatuses.

More specifically, in light of the above, there is a need for animproved grinding apparatus, which by virtue of its design andcomponents, would be able to overcome some of the above-discussed priorart problems.

SUMMARY OF THE INVENTION

In accordance with an aspect of the present invention, there is provideda grinding apparatus for grinding a surface, the grinding apparatusoperable to be powered by a motor including a rotatable motor output,the grinding apparatus comprising:

-   -   a) a plurality of satellites for engaging the surface;    -   b) a carrier for supporting the plurality of satellites, each of        the plurality of satellites being disposed around the motor        output and rotatably mounted to the carrier, the carrier being        rotatably mounted to the motor;    -   c) a plurality of primary gears rotatably mounted within the        carrier, the primary gears disposed about the motor output and        drivable thereby, the primary gears engaging the satellites and        thereby enabling the rotation of the satellites with respect to        the carrier;    -   d) a static gear which is fixed with respect to the motor, the        static gear being co-axial with the motor output; and    -   e) a plurality of secondary gears, each secondary gear being        co-axial with a corresponding one of the primary gears and        rotatable therewith with respect to the carrier, the secondary        gears engaging the static gear and thereby enabling the rotation        of the carrier with respect to the motor.

Preferably, the plurality of primary gears includes a set of innergears, each inner gear engaging the motor output and operable to bedriven thereby; and a set of outer gears, each outer gear engaging arespective one of the inner gears and drivable thereby, each outer gearbeing co-axial with a corresponding one of the satellites.

Preferably the static gear is a crown gear.

Preferably, each secondary gear is mounted to a respective one of theouter gears by an outer axle, each secondary gear and respective outergear thereby being operable to rotate together with respect to thecarrier. Preferably each satellite is mounted to its respective outergear by a respective outer axle.

Preferably, the carrier includes a lower plate, an upper plate and anenclosing wall. Preferably, each outer axle extends through the upperplate such that each secondary gear is mounted outside the carrier.Preferably, each outer axle extends through the lower plate such thateach satellite is mounted outside the carrier opposite the secondarygears.

Preferably, the grinding apparatus further includes an outer casing, theouter casing being fixed to the motor and operable to enclose the topplate and the enclosing wall.

Preferably, the grinding apparatus further includes an edging attachmentwhich includes an edging disk and a bevel gearing assembly mounted tothe carrier and operable to drive the rotation of the edging attachment.

In accordance with another aspect of the present invention, the eachsecondary gear is preferably mounted to one of the inner gears by aninner axle, each secondary gear and respective inner gear therebyoperable to rotate with respect to the carrier.

The invention and its advantages will be better understood by readingthe following non-restrictive description of the preferred embodimentsthereof, made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a floor grinder comprising agrinding apparatus in accordance with an embodiment of the presentinvention;

FIG. 2 illustrates a perspective view of a grinding apparatus inaccordance with an embodiment of the present invention;

FIG. 3 illustrates the grinding apparatus of FIG. 2 with the outercasing removed;

FIG. 4 illustrates the grinding apparatus of the previous FIGs. with themotor hub removed;

FIG. 5 is a perspective view of the grinding apparatus of the previousfigures in cross-section;

FIG. 6 is an exploded view of the grinding apparatus of previous FIGs.;

FIG. 7 is a perspective view of a grinding apparatus according toanother embodiment of the present invention, in cross section; and

FIG. 8 is a perspective view of the grinding apparatus of FIG. 7including an edger attachment;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, the same numerical references refer tosimilar elements. The embodiments shown in the figures are preferred anddisclosed for exemplification purposes only.

As will be apparent to one skilled in the art, in the context of thepresent description the expression “grinding” includes all types ofsurface processing, such as grinding, finishing, polishing, processing,levelling and screeding, surface-preparation, coating overlay removal,honing, and polishing. For this reason, these expressions should not betaken as to limit the scope of the present invention and includes allother kinds of usages or items with which the present invention may beused and could be useful.

In addition, although the preferred embodiments of the present inventionas illustrated in the accompanying drawings comprise various components,and although the preferred embodiments of the floor grinding apparatusand corresponding parts of the present invention as shown, have certaingeometrical configurations as explained and illustrated herein, not allof these components and geometries are essential to the invention andthus should not be taken in their restrictive sense, i.e. should not betaken as to limit the scope of the present invention. It is to beunderstood, as also apparent to one skilled in the art, that othersuitable components and cooperations therebetween, as well as othersuitable geometrical configurations may be used for the floor grindingapparatus according to the present invention, as will be brieflyexplained herein and as can be easily inferred herefrom by one skilledin the art, without departing from the scope of the invention.

In addition, it will be appreciated that certain standard items such asbearings and bearing mounts have been omitted for the sake of clarity.As will be apparent to one skilled in the art, it is preferable that anyaxle or other rotating member be provided with a bearing and, in somecases a bearing mount, positioned between it and whichever element it isrotating with respect to.

In FIG. 1, a floor grinder 100 is illustrated comprising a grindingapparatus 110 which is supported by a frame 112. A handle 114 and wheels116 are provided for manual displacement of the apparatus 100, enablingit to be pushed along a surface during operation. A motor 118 isprovided for driving the grinding apparatus 110 during use. It will beunderstood that the grinding apparatus 110 may similarly be used on amotorized vehicle such as a cart, or self propelled using one of moremotors coupled to the wheels 116, rather than pushed manually, and thatthe motor 118 may be any of a number of types of motor, such aselectric, gas powered, hydraulic or pneumatic. The motor 118 comprises amotor output 119 for transferring the generated power to the apparatus110. The motor output 119 of the motor 118 illustrated in the Figures isa drive shaft 119, although it will be appreciated that alternativeembodiments of the apparatus 110 may be used which receive various othertypes of motor outputs.

With reference now to the preferred embodiment of the invention shown inFIG. 2, the grinding apparatus 110 comprises a motor hub 120 whichattaches an outer casing 122 of the apparatus 110 to the motor 118.Preferably, the outer casing 122 includes a housing plate 121 which isfixed to the hub 120 and a flexible skirt 123. A plurality of grindingdisks 124 (on of which is shown in FIG. 3), also called satellites,extend from beneath the apparatus 110 for engaging the floor during use.The satellites 124 include a plurality of abrasive inserts 126 which canthemselves comprise diamond segments and the like. As will beappreciated, a number of types and varieties of such satellites 124 andsegments 126 are appropriate for use with the grinding apparatus 110. Aswill be further appreciated, the plurality of satellites 124 comprisesfour satellites 124 in the illustrated preferred embodiments, althoughthe use of less or more is equally appropriate.

With additional reference to FIGS. 3 to 6, the preferred embodiment ofthe grinding apparatus 110 of FIG. 2 is illustrated with variouselements removed for clarity. The motor's drive shaft 119 is extendedinto a primary gearing assembly 134, which is housed within a carrier131 along with much of the gearing. The carrier 131 comprises upper andlower plates 132 and an enclosing wall 133. The enclosing wallpreferably isolates much of the gearing in order to prevent dirt, orother contaminants/foreign objects from infiltrating the grindingapparatus 110 or otherwise getting caught therein.

The drive shaft 119 passes through a carrier holder 128 and transfersrotary motion from the motor 118 to the grinding apparatus 110. Thecarrier holder 128 is bolted to the upper carrier plate 132 along itslower extremity. The upper portion of the carrier holder 128 engages theinner race of a bearing assembly 130 (shown in the exploded view of FIG.6). The outer race of the bearing 130 engages the inside of the motorhub 120 while the inner race engages the carrier holder. In this manner,the carrier 131 and its contents are free to rotate with respect to themotor hub 120, the outer casing 122 and the motor 118 itself.

The primary gearing assembly 134 rotates the satellites 124 about theirrespective axes with respect to the carrier 131. The motor drive shaft119 includes a central spur gear 140 engages and transfers power to aplurality of adjacent primary gears 142 and 144 which are rotatablymounted within the carrier 131 and disposed about the drive shaft 119.

In the preferred embodiment illustrated in FIGS. 3 and 4, two sets ofprimary gears 142 and 144 are provided. The primary gears 142 whichengage the spur gear 140 directly are referred to as inner gears 142.The inner gears 142 engage and transfer power to a plurality of outergears 144, which engage the satellites 124 and thereby enable rotationof the satellites 124 with respect to the carrier 131. It will beappreciated that the plurality of outer gears 144 may be equal in numberto the plurality of inner gears 142, as illustrated, or could indeed begreater in an alternative embodiment wherein more than one outer gear144 engages each inner gear 142. It will be further illustrated thatadditional primary gears could be provided between the inner and outergears 142 and 144 for, inter alia, changing the direction of rotation ofthe satellites 124.

The satellites 124 are mounted on outer axles 136 which extend throughthe lower of the two carrier plates 132. Each satellite 124 is fixed toone of the outer gears 144 outside the carrier 131 and both rotatetogether about their respective outer axle 136. In this manner, thepower of the motor 118 is used to rotate the satellites 124 about thecarrier 131 by transferring the rotational motion of the drive shaft 119via the central gear 140, to each of the inner gears 142 and then toeach satellite 124 via its respective outer gear 144. Preferably, thegears 140, 142, 144 and 154 are helical gears.

In addition, a secondary gearing assembly 150 is provided for rotatingthe carrier 131 and the satellites 124 about the grinding apparatus 110itself, i.e. for enabling active planetary motion. In the preferredembodiment illustrated in FIGS. 3 and 4, the secondary gearing assembly150 includes a plurality of secondary gears 152 and a static gear 154.The static gear 154 is preferably a crown gear 154 and is attached tothe underside of the housing plate 121 of the outer casing 122 such thatit remains fixed with respect to the motor 118. Each secondary gear 152co-axial and rotates with a respective one of the primary gears 142 and144. Preferably each secondary gear 152 is fixed to a respective outergear 144 and the two are operable to rotate together about the carrier131.

Each outer gear 144 and secondary gear 152 pair are fixed at oppositeends of an outer axle 136 which extends through the upper carrier plate132 and pivots with respect to the lower carrier plate 132. As such, thesecondary gears 152 are mounted outside the carrier 131. Each inner gear142 is provided with a respective inner axle 156 with which it is ableto rotate about the carrier 131.

As the central spur gear 140 drives the primary gears 142 and 144, thecorresponding rotation of the secondary gears 152 and their engagementwith the crown gear 154 drive the carrier 131 and the elements mountedthereto about the crown gear 154 and with respect to the motor 118. Itwill be appreciated that the rotation of the satellites 124 about theaxes 136 is opposite to the direction of the planetary rotation of thoseaxes about the static gear 154. This opposite rotation advantageouslyincreases stability and eases grinding.

This planetary motion occurs within the outer casing 122 which is fixedto the motor 118 via the motor hub 120. As shown most clearly in FIG. 3,the engagement of the secondary gears 152 and the crown gear 154preferably occurs above the upper carrier plate 132, although it will beappreciated that other arrangements are within the scope of the presentinvention.

FIG. 7 illustrates another preferred embodiment of the grindingapparatus 110 . Herein, the secondary gears 152 are co-axial with theinner gears 142 and attached to the inner axles 156, and the crown gearhas been replaced with a static gear 154 having outward facing teeth.

Due to their large circular shape, conventional grinding apparatuseshave difficulty grinding the edges of a surface, such as a junction witha wall, and leave a gap of at least one inch which cannot be processed.With reference to FIG. 8, the grinding apparatus 110 of FIG. 7 isprovided with an edging attachment 170. The edging attachment 170comprises two edging disks 172 which are driven by a bevel gear 174fixed to the upper carrier plate 132. A bevel gearing assembly 176transfers the rotation of the upper carrier plate 132 to each edgingdisk 172 by respective horizontal shafts 178, vertical shafts 180 andbevel gears 182. For clarity, the supports for these elements have notbeen illustrated.

The pressure exerted by the edging disks 172 is preferably adjustable byhand, or by an electric motor controlled from a control panel. Theedging disks 172 are preferably flexible so as to follow the level of anuneven surface.

The grinding apparatus 110 may further be provided with an automaticelectronic levelling mechanism and ultrasonic or infrared gloss sensorsfor automatically adjusting rotation speed and/or apparatus alignmentand pressure. Furthermore, the grinding apparatus 110 may be equippedwith positional sensors operable to navigate the grinding apparatus 110along a given surface in response to an initial user input or externalsensor stimuli which senses walls, obstacles and the like so as to berun without an operator. The grinding apparatus 110 may also be providedwith automatic cooling sensors which detect the satellites' temperatureand distribute a cooling substance, such as a water mist, if theiroperating temperature reaches a predetermined maximum.

As being now better appreciated, the present invention is an improvementand presents several advantages over other related apparatuses known inthe art. Indeed, the present invention is particularly advantageous inthat it provides a robust planetary gear assembly, instead of abelt-driven assembly, which will allow the grinding apparatus to operateat high speeds. As will be appreciated by one skilled in the art, higheroperating speeds advantageously allow faster grinding, which saves time,but also use of coarser grinding material. It will further beappreciated that the above-described grinding apparatuses are operableto work on all types of floor, for example concrete, terrazzo, ornatural stones such as granite and marble. It will also be appreciatedthat the above-described grinding apparatuses are usable for any type ofgrinding or other surface processing application, such as finishing,polishing, processing, levelling and screeding, surface-preparation,levelling, coating overlay removal, honing, and polishing.

Of course, numerous modifications could be made to the above-describedembodiments without departing from the scope of the invention, asapparent to a person skilled in the art.

1. A grinding apparatus for grinding a surface, the grinding apparatusoperable to be powered by a motor comprising a rotatable motor output,the grinding apparatus comprising: a) a plurality of satellites forengaging the surface; b) a carrier for supporting the plurality ofsatellites, each of the plurality of satellites being disposed aroundthe motor output and rotatably mounted to the carrier, the carrier beingrotatably mounted to the motor; c) a plurality of primary gearsrotatably mounted within the carrier, the primary gears disposed aboutthe motor output and drivable thereby, the primary gears engaging thesatellites and thereby enabling the rotation of the satellites withrespect to the carrier; d) a static gear which is fixed with respect tothe motor, the static gear being co-axial with the motor output; and e)a plurality of secondary gears, each secondary gear being co-axial witha corresponding one of the primary gears and rotatable therewith withrespect to the carrier, the secondary gears engaging the static gear andthereby enabling the rotation of the carrier with respect to the motor.2. The grinding apparatus of claim 1, wherein the plurality of primarygears comprises: a) a set of inner gears, each inner gear engaging themotor output and operable to be driven thereby; and b) a set of outergears, each outer gear engaging a respective one of the inner gears anddrivable thereby, each outer gear being co-axial with a correspondingone of the satellites.
 3. The grinding apparatus of claim 2, wherein thestatic gear is a crown gear.
 4. The grinding apparatus of claim 3,wherein each secondary gear is mounted to a respective one of the outergears by an outer axle, each secondary gear and respective outer gearthereby being operable to rotate together with respect to the carrier.5. The grinding apparatus of claim 4, wherein each satellite is mountedto its respective outer gear by a respective outer axle.
 6. The grindingapparatus of claim 5, wherein the carrier comprises a lower plate, anupper plate and an enclosing wall.
 7. The grinding apparatus of claim 6,wherein each outer axle extends through the upper plate such that eachsecondary gear is mounted outside the carrier.
 8. The grinding apparatusof claim 7, wherein each outer axle extends through the lower plate suchthat each satellite is mounted outside the carrier opposite thesecondary gears.
 9. The grinding apparatus of claim 1, furthercomprising an outer casing, the outer casing being fixed to the motorand operable to enclose the top plate and the enclosing wall.
 10. Thegrinding apparatus of claim 9, wherein the static gear is fixed to theouter casing.
 11. The grinding apparatus of claim 1, wherein theplurality of primary gears, the static gear and the plurality ofsecondary gears are helical gears.
 12. The grinding apparatus of claim2, wherein each secondary gear is mounted to a respective one of theinner gears by an inner axle, each secondary gear and respective innergear thereby being operable to rotate with respect to the carrier. 13.The grinding apparatus of claim 1, further comprising an edgingattachment, the edging attachment comprising an edging disk and a bevelgearing assembly mounted to the carrier and operable to drive therotation of the edging attachment.